I have a Blackberry 8700g with BIS and I visit my account at my.t-mobile.com
There is an option to set up Blackberry Internet email there. When I try to set up a POP account I only see an IMAP setting there. Nothing other option is available. Is this why I am have difficulty receiving my work/pop email?

I had the same problem. It auto-configures the mail settings. If your server supports IMAP, it configures IMAP and doesn't let you change to POP. I actually had to temporarily disable IMAP support on my mail server. I deleted the account and set it back up. It said it couldn't configure the account. I manually configured with my settings and in a few minutes, I had my emails coming in through POP. I don't know if you have access to your mail server configuration, so I can't tell you how to do it otherwise. Maybe someone else knows of a way to "trick" the server into letting you manually configure.

When adding the account put in the wrong password. It will fail and take you to the advanced options. You can specify how you want the account to be set up by choosing the 'I will provide the settings for this account.'